In U.S. Pat. No. 2,807,820 to Dinhofer, the straddle-type tooth brush disclosed therein comprises an elongated rod-like device which comes in two parts, but when assembled, the device comprises a pair of elongated arms having outboard end portions and adapted for insertion in the mouth of the person whose teeth are to be cleaned, a tooth brushing implement that is connected with the arms for cleaning the teeth, and a handle that is operable to support the arms adjacent a row of teeth while the implement is applied thereto. The arms project from the distal end of the handle in generally spaced parallel relationship to one another, with an elongated slot extending therebetween, and are rigidly interconnected with the handle so as to form relatively rigid extensions of the same, longitudinally thereof. The implement comprises a foldable brush-forming head which is separate from the device, but operatively connected with the arms to straddle the slot at the outboard end portions of the arms on an axis of the implement extending from arm to arm crosswise the length of the slot. The brush-forming head has three sections in the body thereof comprising a pair of spaced wings, and a midsection in the space therebetween, which are serially interconnected with one another along the aforesaid axis of the implement. The head also has brush-forming means on corresponding sides of the wings, and when the head is folded and put to use, it is operatively arranged on the arms so that the wings are reentrantly folded about the midsection transverse the axis of the implement, with the brush-forming sides thereof folded relatively toward one another, but spaced apart from one another by a gap having a mouth opposite the midsection of the head for the introduction of the teeth to the gap. Additionally, the brush-forming head has added portions thereof, in the form of channeled sections, which are interposed between the respective wings and the midsection thereof, axially of the implement, to be used in mounting the implement on the arms when the wings have been reentrantly folded about the midsection as indicated.